ROFLMAO... is that inner fire or outer fire?

Both, I'd guess.

Back on topic - Here's a little snippet I ran across:

<< "Footcandles (fc) = Total Lumens (lm) ÷ Area in Square Feet

1 Lux (lx) = 1 Footcandle (fc) x 10.76

Lux = Total Lumens ÷ Area in Square Meters

The human eye is a sophisticated piece of machinery; it is able to adjust to a wide range of light levels, including about 10,000 footcandles on a sunny day to about 0.01 footcandles under full moonlight. " >>

Hmmm- seems my minus 6 orders of magnitude was right on target (at full moon). If we assume that the moon reflects the entire spectrum (it does NOT - it's less), we can assume that the energy landing on a given area at full moon is equal to 10 to the minus 6th the amount of energy in sunlight.

Let's assume that the smallest optic we can manage to make a fire with in direct sunlight is 1 inch in diameter. That's about 0.785 square inches. A million times greater area and we're looking at a lens that has an area of about 785,000 square inches. I think that works out to a radius of about 500 inches, so a diameter of about 1000 inches. Hmmmm... a lens about 83 feet across might be a little hard to stick in my pocket... but of course, this is only theory. Somebody check my math.

In practice, no way is anyone going to be able to make fire from direct moonlight.

Go get him, Aardwolfe!